One of the main advantages to humeral resurfacing arthroplasty is the fact that bone is saved and a total shoulder replacement (TSR) is still possible later, if needed.
Shoulder resurfacing smooths the diseased bone and covers it with a metal cap. The head of the humerus (upper arm bone), surface of the acetabulum (shoulder socket), or both may be involved with a resurfacing procedure.
But if this procedure fails for any reason, then the patient can have a revision surgery to remove the bone and replace it with a TSR. Infection leading to loosening of the implant is the most common reason to remove and replace the joint resurfacing.
But if your implant wasn’t loose at the time of the revision operation, then something else may have been causing your painful symptoms. There isn’t always a way to know for sure what this might have been. It could be there was an alignment problem with the joint resurfacing implant.
Or the shape of the humeral or the acetabulum may have been slightly off-center leading to mechanical problems. Sometimes cystic changes and capsular thickening occur within the joint leading to problems.
Last, but not least, microscopic neurovascular damage at the time of the first procedure could have lead to chronic pain. This may or may not improve with revision surgery.